Kalshi & Polymarket: prediction markets

A prediction market is a trading platform where users buy and sell contracts tied to the outcome of future events. Unlike traditional bookmakers who set the odds, here it is the participants themselves who set the price through supply and demand. Each contract trades between $0 and $1 (or 0 and 100 cents). The price reflects the probability estimated by the market. For example, a contract at $0.65 means the market estimates the event's probability at 65%. If the event happens, the contract pays $1. Otherwise it is worth $0. It is a more transparent and often more accurate system than traditional bookmakers, as it aggregates the collective intelligence of thousands of participants.

Polymarket is the largest prediction market — decentralised, built on the Polygon blockchain and funded with the USDC stablecoin. You buy Yes/No shares priced in cents, with no stake limits and light KYC; the trade-offs are that it needs crypto and access is restricted in some regions. Kalshi is the US-regulated counterpart, overseen by the CFTC and funded in US dollars — the legal, institutional route for US residents. It lists Yes/No event contracts from 1¢ to 99¢, with a more curated (and sometimes less liquid) market list. We cover each one step by step — deposits, trading and resolution — in our dedicated Polymarket and Kalshi guides. The table below is the quick comparison.

In short: Polymarket for international crypto users who want maximum freedom, Kalshi for Americans who prefer a regulated framework with dollar deposits.

Prices are quoted in cents, and the cent price is the implied probability — 65¢ means a 65% chance. To convert to sportsbook formats, decimal odds = 100 ÷ cents (65¢ → 1.54), and the implied probability is simply the price itself. Our dedicated guide on reading Polymarket and Kalshi odds covers Yes/No shares, bid-ask spreads and every conversion in detail — and the odds converter on the Tools page does all four formats instantly.

1. News trading: Buy or sell quickly after major news before the market fully adjusts. Speed is essential. 2. Arbitrage: Compare prices between Polymarket, Kalshi and traditional bookmakers. Gaps often exist, especially on less liquid markets. 3. Fading the consensus: When the market seems to overreact to news (panic buy/sell), take the opposite position. Markets often correct. 4. Hedging: Use prediction markets to hedge your traditional sports bets or vice versa. 5. Hold to expiry vs trade: You don't have to wait for the final result. If your contract bought at 30¢ rises to 70¢, you can sell and lock in gains.